I was thinking a few days ago about the decomposition that occurred with the bodies of the Toa Mata in their canisters... and how they were like two and a half times taller than the matoran at the time. I'm not sure if the matoran can smell, but Tahu probably smelled pretty ghastly, and still had some open sores or rotten parts by the time that he arrived in Ta-Koro.
No wonder Jaller's guard was terrified of him; to us, he'd be a twelve-foot-tall zombie.
This one is lifted from the phenomenal Fridge Horror page for G1 on the TVTropes website.
So, the Mask of Life can only manipulate things that are alive or were once alive, right? And Bara Magna was the site of a mass war that went on for decades at the very least, right? On Bara Magna, the mask pulls together a body for Mata Nui out of... sand. An inorganic material. Or so we thought at the time.